Round balers are used to produce bales from stalk-shaped agricultural harvested produce. Such round balers have a bale-forming chamber and associated pressing means. After completion and optional wrapping of a bale with mesh, twine, or film, this bale is ejected toward the back out of the bale-forming chamber, after a rear door has been opened or a pivoting part holding a bale pressing element has been pivoted upward, in order to clear the path for the bale.
When leaving the bale-forming chamber, on one hand, the bale still has a not insignificant rotational energy from the bale-forming and optional wrapping process and, on the other hand, also gains kinetic energy while rolling out of the bale-forming chamber when it rolls down a rear-facing unloading ramp of the round baler. This kinetic energy can result in the bale rolling on the ground an undesired distance. In addition, it impacts the unloading ramp at a rather high speed, which could damage the wrapping material. The unloading ramp therefore is to be constructed with sufficient flexibility in the prior art in a rather complicated way in order to prevent this problem.
In the prior art (DE 103 39 652 A1), it has been proposed to attach a door to the rear side of the bale-forming chamber of the round baler, wherein this door can pivot about a vertical or approximately vertical pivoting axis and is used as a retaining device for the bale, in that it comes in contact with the end side of the ejected bale and brakes it. Such a door, however, also means additional costs and cannot influence the speed at which the bale reaches the unloading ramp, because the bale contacts the door only at a later time.
Furthermore, round balers have been described with side walls or side wall parts that move in the lateral direction, which are moved into an inner position during the forming of a bale and are moved outward for ejecting the bale, in order to reduce the friction forces of the bale during the ejection. Refer here to U.S. Pat. No. 4,334,467 A, DE 39 20 377 A1, DE 10 2005 036 181 A1, EP 1 264 531 A1, EP 1 364 574 A1, and EP 1 396 187 A2. When the bale is rolled out, the force exerted by the side walls on the bale is thus reduced by a relatively small value that does not lead to significant braking of the bale while it is rolling out and does not solve the mentioned problem.
According to DE 10 2007 012 174 A1, for the unloading process, the side wall is moved into a position in which a specified friction detected by sensors is produced. Here, greater costs for the controller are required, including an associated actuator for moving the side wall. The movement should guarantee an ejection of the bale, so that a significant braking effect also cannot be assumed here.